    * {
        margin: 0;
        padding: 0;
    }

    #header {
        width: 100%;
        background: #ffffff;
        box-shadow: 2px 3px 5px;
        height: 60px;
        padding: 10px 0;
        background-color: blueviolet;
    }

    .header {
        width: 1200px;
        margin: auto;
    }

    .header-logo {
        float: left;
    }

    .header-nav {
        float: right;
    }

    .header-logo img {
        float: left;
        width: auto;
        height: 60px;
    }

    .header-logo h4 {
        float: left;
        margin-left: 15px;
        height: 60px;
        line-height: 60px;
        font: size 22px;
        font-weight: normal;
        letter-spacing: 2px;
    }

    .header-nav ul li {
        float: left;
        height: 60px;
        line-height: 60px;
        margin: 0 20px;
    }

    .header-nav ul li a {
        text-decoration: none;
        color: #333333;
    }

    body {
        font-size: 20px;
    }

    .header-nav ul li a:hover {
        color: red;
    }

    .header-nav ul .aaa a {
        color: red;
    }

    table {
        text-align: center;
        width: 100%;
    }
    .banner{
        width: 1200px;margin: 20px auto;display: flex;justify-content: left;
    }
    .banner-left img{ width: 600px;height: 400px;object-fit: cover;}
    .banner-left{ width:600px;height:380px;}
    .banner-right{width:380px;}
    td:nth-child(2n){
        background-color: plum
    }
    td:nth-child(1){
        background-color:skyblue
    }
    td:nth-child(3){
        background-color:skyblue
    }